Oil pan structure for internal combustion engine

Abstract

An oil pan ( 2 ) fixed on an engine mounted on a vehicle with an inclination angle has a first baffle plate ( 4 ), a portion of which is horizontally disposed, in the inside of the oil pan, a second baffle plate ( 5 ) disposed vertically between the first baffle plate ( 4 ) and the bottom of the oil pan ( 2 ) such that said second baffle plate ( 5 ) partitions the space into two compartments, and an oil passageway between the two compartments. Since the oil passage way reduces mixed air bubbles in the oil when the oil flows through the passageway, either compartment has less mixed air bubbles such that the oil surface levels in the two compartments may be equalized and that the aeration may be reduced.

What is claimed is:  
     
       1. An oil pan structure on an engine which is mounted in a vehicle body with a cylinder axial line of a cylinder block of said engine inclined to a vertical face, said engine including a crankshaft having a rotation axis, the oil pan structure having a horizontal bottom face section affixable on said engine, said oil pan structure comprising: 
       a top face section affixable to said engine parallel to said rotation axis;  
       said horizontal bottom face section parallel to said rotation axis;  
       said top face section inclined to said horizontal bottom face at an angle acute to said horizontal bottom face;  
       said top face section continuous with said horizontal bottom face along a connecting radius;  
       said top face section in a plane parallel to a tangent extended from said external crank shaft;  
       a first and a second side face sections perpendicular to said crankshaft;  
       said first and said second side face sections joining said top face section to said horizontal bottom face section bounding an oil retention area opposite said external crank shaft;  
       said oil retention area effective to receive oil from said external engine and said external crank shaft, retain said oil on a plurality of transport surfaces, and transport said oil along said transport surfaces to form an oil pool having a surface substantially parallel to said horizontal bottom face;  
       a first baffle plate disposed in said oil pan structure between said first and said second side face, and continuously joining said top face section to said horizontal bottom face section;  
       said first baffle plate effective to receive said oil flung from said external crankshaft and said engine, and transport said oil to said oil pool without agitating said oil pool and entraining air in said oil;  
       said first baffle plate having a horizontal portion, a first and a second sloped portion;  
       said horizontal portion parallel said horizontal bottom face section opposite said oil surface;  
       said first sloped portion extends from said top face section to said horizontal portion and directs said oil to at least said horizontal portion thereby reducing entrained air in said oil and preventing additional entrainment;  
       said second sloped portion extends from said horizontal portion to said horizontal bottom face;  
       said first and second sloped portions substantially parallel a first joining surface of said external engine;  
       said first baffle plate having at least a first opening on said second sloped portion adjacent said horizontal bottom face;  
       said at least first opening effective to receive oil from said first sloped portion, said horizontal section, said second sloped portion, and said external engine and direct said oil to a bottom portion of said oil pan structure below said horizontal portion without agitating and dripping said oil thereby minimizing air entrainment in said oil;  
       said first baffle plate including at least a third opening;  
       said third opening on at least said first sloped portion adjacent said top face section;  
       said third opening effective to receive said oil thrown from said external crankshaft and direct said oil to said bottom portion of said oil pan structure;  
       a second baffle plate disposed vertically between said first baffle plate said horizontal bottom surface;  
       said second baffle plate effective to divide said bottom portion into a first and a second compartment;  
       said second baffle plate having at least a second opening; and  
       said second opening effective to transport said oil from said first compartment to said second compartment and maintain substantially equivalent oil surface heights in said first and said second compartment without agitating said oil and maximizing an oil residence time in said first compartment before transporting said oil to said second compartment, whereby said entrained air in said oil is minimized in said second compartment.  
     
     
       2. The oil pain structure of  claim 1 , wherein: 
       said first baffle plate further comprises a plurality of first openings adjacent said second sloped portion adjacent said horizontal bottom face.  
     
     
       3. The oil pan structure of  claim 1 , wherein: 
       said third opening is positioned on said at least second sloped portion and said horizontal portion and effective to receive said oil flung from said crankshaft rotation and direct said oil to said bottom portion of said oil pan structure whereby air entrainment is minimized in said oil.  
     
     
       4. The oil pan structure of  claim 3 , wherein: 
       said third opening is adjacent to a housing of said oil pan structure.  
     
     
       5. The oil pan structure of  claim 1 , wherein: 
       said at least second opening is a plurality of openings effective to transport said oil without agitating said oil.  
     
     
       6. The oil pan structure of  claim 1 , further comprising: 
       an oil strainer hole in said horizontal portion formed to receive an external oil strainer for transporting said oil disposed near a bottom of said oil pan structure in one of said first and said second compartment partitioned by said second baffle plate.  
     
     
       7. The oil pan structure of  claim 6 , further comprising: 
       said third opening being over said other of said first and said second compartment in which said oil strainer is not disposed.  
     
     
       8. The oil pan structure of  claim 7 , wherein: 
       said third opening is positioned on said at least second sloped portion and said horizontal portion and effective to receive said oil from said crankshaft rotation and direct said oil to said bottom portion of said oil pan structure whereby air entrainment is minimized in said oil.  
     
     
       9. The oil pan structure of  claim 7 , wherein: 
       said third opening is adjacent to a housing of said oil pan structure.